Algebra please please help

Question

Factor completely. 25x^2 + 40xy + 16y^2

Factor. s^2(t – u) – 9t^2(t – u)

Answer 1

For the top: Hint: a² + 2ab + b² = (a+b)² 

For the bottom: factor out (t-u) from both terms to get (t-u)(s² - 9t²). Factor the second set of parentheses. (Hint: Difference of two squares)